Method for reduction of SO2 emission for fossil fired boiler

摘要

Apparatus and method for the efficient and economic removal of sulfur dioxide from gases. In which the gas is contacted with neutralizing values obtained from pressure hydrated lime or pressure hydrated dolomitic lime, i.e. calcined limestone or dolomite and slaked with water under elevated temperature and pressure. The pressure hydrated lime or dolomitic lime may be used in conjunction with a wet scrubber, in a spray dryer or dry scrubber, or directly introduced into the gas passages of a boiler, upstream or downstream of the air preheater, or in the boiler output ducting or the inlet of an electrostatic precipitator. The use of pressure hydrated lime or pressure hydrated dolomitic lime greatly enhances the efficiency of sulfur dioxide removal, thereby providing for enhanced use of base values and a more rapid rate of reaction. The confined zone dispersion scheme permits a partial SO2 removal (10%-50%) without a scrubber, only by atomizing a slurry of pressure hydrated lime or pressure hydrated dolomitic lime into the flue gas duct of the boiler.